冬小麦需水关键期的降水预报评估与应用对策分析

Assessment of Rainfall Forecast and Its Application Countermeasure for Winter Wheat's Critical Period of Water Requirement

有效利用冬小麦需水关键期的降水预报是充分利用自然降水并达到节水灌溉的有效策略之一。基于蚌埠市气象台2007-2013年冬小麦需水关键期（3月11日-5月31日）的24-120h降水预报和地面降水观测资料,采用正确率、风险评分、概率统计以及相对特征运行曲线（ROC曲线）四种方法检验评估降水预报的准确率,并分析其在冬小麦需水关键期节水灌溉决策中的应用。结果表明,降水预报对无雨天气或弱降水过程的预报准确率较高,对强降水天气过程的预报,总体上表现为预报量级偏低,但对降水过程具有识别能力;预报为小雨及以下量级时,可按照冬小麦的实际需水量进行灌溉,预报为中雨及以上量级时,可适当推迟灌溉;随着预见期延长,预报准确率整体呈下降趋势,灌溉时应根据最新天气预报和降水实况,重新确定灌溉策略,制定合适的灌溉量。

It is one of the effective strategies to make good use of rainfall forecast during key water requirement periods of winter wheat to get the utmost out of natural rainfall and achieve the result of water-saving irrigation.Based on the24-120 hrainfall forecast and observation data of Bengbu Meteorological Observatory during key water requirement periods of winter wheat,this paper evaluates the accuracy of rainfall forecast and analyzes its application in water-saving irrigation decision-making by using the methods of Percentage Correct（PC）,Treat Score（TS）,Probability and ROC curve.Mainly,our study presents the following three results.The performance of rainfall forecast is relatively higher for no rain weather or weak precipitation;the forecast magnitude of strong precipitation is lower,but it can be distinguished.When the forecast is light rain or below,the irrigation can be conducted according to the actual water demand of winter wheat.When the forecast is moderate rain or above,the irrigation quota can be postponed accordingly.The performances of rainfall forecast gradually decline with the extension of period of validity.The irrigation decision-making and the irrigation amount should be adjusted to the latest weather forecasts and rainfall observations when irrigating.